CN107276655A - Signal processing method and system - Google Patents
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- CN107276655A CN107276655A CN201610217039.8A CN201610217039A CN107276655A CN 107276655 A CN107276655 A CN 107276655A CN 201610217039 A CN201610217039 A CN 201610217039A CN 107276655 A CN107276655 A CN 107276655A
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2647—Arrangements specific to the receiver only
- H04L27/2655—Synchronisation arrangements
- H04L27/2657—Carrier synchronisation
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
- H04B7/0613—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
- H04B7/0667—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of delayed versions of same signal
- H04B7/0669—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of delayed versions of same signal using different channel coding between antennas
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/08—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station
- H04B7/0837—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station using pre-detection combining
- H04B7/0842—Weighted combining
- H04B7/0848—Joint weighting
- H04B7/0851—Joint weighting using training sequences or error signal
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/0202—Channel estimation
- H04L25/0204—Channel estimation of multiple channels
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/0202—Channel estimation
- H04L25/024—Channel estimation channel estimation algorithms
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2647—Arrangements specific to the receiver only
- H04L27/2655—Synchronisation arrangements
- H04L27/2689—Link with other circuits, i.e. special connections between synchronisation arrangements and other circuits for achieving synchronisation
- H04L27/2695—Link with other circuits, i.e. special connections between synchronisation arrangements and other circuits for achieving synchronisation with channel estimation, e.g. determination of delay spread, derivative or peak tracking
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Abstract
The invention provides a kind of signal processing method, including：Pretreatment is performed to the reception signal from transmitting terminal, the time domain data signal and the training sequence signal of time domain that the reception signal is generated by initial frequency domain data signal after inverse fourier transform are constituted and the training sequence signal of the time domain includes the training sequence based on LAS codes, and execution pretreatment includes：Pretreatment is performed to the reception signal using the training sequence based on LAS codes.The present invention is higher to the synchronization accuracy of time and frequency, thus can improve the success rate and access speed of user access network, makes Consumer's Experience better.
Description
Technical field
The present invention relates generally to wireless communication system, more particularly to a kind of signal processing method and system.
Background technology
Cordless communication network be widely deployed with provide such as voice, video, grouped data, information receiving,
The various communication services such as broadcast.These wireless networks can be propped up by sharing available Internet resources
Hold the multi-access network of multiple users.The example of this kind of multi-access network include CDMA (CDMA) network,
Time division multiple acess (TDMA) network, frequency division multiple access (FDMA) network, orthogonal FDMA (OFDMA)
Network and Single Carrier Frequency Division Multiple Access (SC-FDMA) network.
With global mobile communication constantly enhanced demand, the frequency resource of radio communication is more nervous.Therefore,
Except the above-mentioned conventional highfrequency spectrum utilization rate based on TDM (time division multiplexing), FDM (frequency division multiplexing)
Outside wireless communication system, it is also proposed that there is the more radical communication plan of more high usage for frequency spectrum.
System is exactly for overlapped time division multiplexing (Overlapped Time Division Multiplexing, OvTDM)
Such a scheme for improving system spectral efficiency.In OvTDM systems, not only need not between symbol
It is mutually isolated, and can have very strong mutual overlapping.In other words, OvTDM systems are by artificially drawing
Enter the overlapping between symbol, transmit data sequence in time-domain parallel using multiple symbols, frequency spectrum greatly improved
Utilization rate.
Overlapping frequency division multiplexing (Overlapped Frequency Division Multiplexing, OvFDM) system
It is the scheme that another improves system spectral efficiency., can between sub-carrier band in OvFDM systems
It is more stronger than orthogonal frequency division multiplex OFDM overlapping to have.Pass through weight higher between each sub-band in frequency domain
Folded degree, further increases the availability of frequency spectrum on the basis of ofdm system.
Although there is corresponding reception demodulation scheme to exclude letter for above-mentioned OvTDM systems and OvFDM systems
Number time domain or frequency domain overlapping brought interference, but the availability of frequency spectrum is greatly improved still to signal
Reception propose requirements at the higher level.
Therefore, OvTDM systems and OvFDM systems need the network insertion scheme of higher performance.And show
The m-sequence that some communication systems are used can not meet demand for training sequence.
The content of the invention
The brief overview of one or more aspects given below is to provide to the basic comprehension in terms of these.This is general
The extensive overview of the not all aspect contemplated is stated, and is both not intended to identify the key of all aspects
Or the decisive key element also non-scope attempted to define in terms of any or all.Its unique purpose is will be with simplification
Some concepts that form provides one or more aspects think the sequence of more detailed description given later.
It is an object of the present invention to when using M sequence for existing communication system for training sequence, due to
M sequence auto-correlation and cross correlation are poor, cause system synchronization procedure success rate low, and network insertion is slow
Defect is there is provided a kind of communication means and system, to overcome above mentioned problem.
According to an aspect of the present invention there is provided a kind of signal processing method, including：
Pretreatment is performed to the reception signal from transmitting terminal, the reception signal is by initial frequency domain data signal
The time domain data signal and the training sequence signal composition of time domain and the time domain generated after inverse fourier transform
Training sequence signal include the training sequence based on LAS codes, the execution pre-process include：
Pretreatment is performed to the reception signal using the training sequence based on LAS codes.
In one example, this performs pretreatment using the training sequence based on LAS codes to the reception signal
Including at least one of：
Timing Synchronization is performed to the reception signal using the training sequence based on LAS codes；
Carrier synchronization is performed to the reception signal using the training sequence based on LAS codes；Or
Channel estimation is performed to the reception signal using the training sequence based on LAS codes.
In one example, the training sequence includes at least one LAS short code [Xlas]SN, SN is the LAS
The length of short code, this performs pretreatment using the training sequence based on LAS codes to the reception signal includes：
Timing Synchronization is performed to the reception signal using at least one LAS short code.
In one example, the training sequence includes two LAS short codes, and this is using this based on LAS codes
Training sequence performs pretreatment to the reception signal also to be included：
Carrier synchronization is performed to the reception signal using two LAS short codes.
In one example, the training sequence includes：[0]SN,[Xlas]SN,[0]SN,[Xlas]SN, wherein [0]SNFor length
Spend 0 sequence for SN.
In one example, the training sequence also includes two LAS long codes [Xlas]LN, LN is the LAS length
The length of code, this performs pretreatment using the training sequence based on LAS codes to the reception signal also includes：
Using two LAS long codes to the secondary execution carrier synchronization of the reception signal Jing Guo carrier synchronization.
In one example, this performs pretreatment using the training sequence based on LAS codes to the reception signal
Also include：
Channel is performed using any one of this two long LAS codes to the reception signal through carrier synchronization to estimate
Meter.
In one example, this performs pretreatment using the training sequence based on LAS codes to the reception signal
Also include：
Channel estimation twice is performed to the reception signal through carrier synchronization using this two long LAS codes.
In one example, the training sequence includes：[0]SN,[Xlas]SN,[0]SN,[Xlas]SN,[Xlas]LN,[Xlas]LN,
Wherein [0]SNFor 0 sequence that length is SN.
According to another aspect of the present invention there is provided a kind of signal processing apparatus, including：
Pretreatment unit, for performing pretreatment to the reception signal from transmitting terminal, the reception signal is by first
Time domain data signal and the training sequence of time domain that the frequency domain data signal of beginning is generated after inverse fourier transform
Signal is constituted and the training sequence signal of the time domain includes the training sequence based on LAS codes, the pretreatment list
Member performs pretreatment using the training sequence based on LAS codes to the reception signal.
In one example, pretreatment unit includes at least one of：
Time synchronization unit, it is fixed for being performed using the training sequence based on LAS codes to the reception signal
When it is synchronous；
Carrier synchronization unit, for performing load to the reception signal using the training sequence based on LAS codes
Ripple is synchronous；Or
Channel estimating unit, for performing letter to the reception signal using the training sequence based on LAS codes
Estimate in road.
In one example, the training sequence includes at least one LAS short code [Xlas]SN, SN is the LAS
The length of short code, the pretreatment unit includes the time synchronization unit, and the time synchronization unit is further used for
Timing Synchronization is performed to the reception signal using at least one LAS short code.
In one example, the training sequence includes two LAS short codes, and the pretreatment unit also includes should
Carrier synchronization unit, the carrier synchronization unit is further used for believing the reception using two LAS short codes
Number perform carrier synchronization.
In one example, the training sequence includes：[0]SN,[Xlas]SN,[0]SN,[Xlas]SN, wherein [0]SNFor length
Spend 0 sequence for SN.
In one example, the training sequence also includes two LAS long codes [Xlas]LN, LN is the LAS length
The length of code, the carrier synchronization unit is further used for using two LAS long codes to passing through carrier synchronization
The secondary execution carrier synchronization of the reception signal.
In one example, the pretreatment unit also includes the channel estimating unit, and the channel estimating unit is entered
One step is used to perform channel to the reception signal through carrier synchronization using any one of this two long LAS codes
Estimation.
In one example, the pretreatment unit also includes the channel estimating unit, and the channel estimating unit is entered
One step is used to perform channel estimation twice to the reception signal through carrier synchronization using this two long LAS codes.
In one example, the training sequence includes：[0]SN,[Xlas]SN,[0]SN,[Xlas]SN,[Xlas]LN,[Xlas]LN,
Wherein [0]SNFor 0 sequence that length is SN.
The present invention has following beneficial effect：The present invention by designing using LAS codes as training in systems
Sequence, it is zero everywhere beyond preferable impulse function, origin to be in origin using LAS codes auto-correlation function,
And cross-correlation function is zero characteristic everywhere, solves practical communication system and use M sequence for training sequence
When, because M sequence auto-correlation and cross correlation are poor, cause system synchronization procedure success rate relatively low,
The problem of network insertion is slow.Realize when using LAS codes for training sequence, in signal processing,
It is higher to the synchronization accuracy of time and frequency including Timing Synchronization, carrier synchronization, channel estimation, thus can
The success rate and access speed of user access network are improved, makes Consumer's Experience better.
Brief description of the drawings
After the detailed description of embodiment of the disclosure is read in conjunction with the following drawings, this better understood when
The features described above and advantage of invention.In the accompanying drawings, each component is not necessarily drawn to scale, and with class
As the component of correlation properties or feature may have same or like reference.
Fig. 1 shows the block diagram of the transmitting terminal modulation module of OvTDM systems；
Fig. 2 shows the block diagram of the signal pre-processing module of the receiving terminal of OvTDM systems；
Fig. 3 shows the block diagram of the receiving terminal sequence detection module of OvTDM systems；
Fig. 4 shows the modulation module block diagram of the transmitting terminal of OvFDM systems；
Fig. 5 shows the block diagram of the signal pre-processing module of the receiving terminal of OvFDM systems；
Fig. 6 shows the block diagram of the signal detection module of the receiving terminal of OvFDM systems；
Fig. 7 shows the autocorrelation performance of M sequence；
Fig. 8 shows the autocorrelation performance of LAS codes；
Fig. 9 shows the distribution map of the autocorrelation result of Timing Synchronization；
Figure 10 shows the schematic diagram for detecting the training sequence under two peak value situations；
Figure 11 shows the block diagram of the time synchronization unit of receiving terminal according to an aspect of the present invention；
Figure 12 shows the flow chart of time synchronization method according to an aspect of the present invention；
Figure 13 shows the block diagram of carrier synchronization unit according to an aspect of the present invention；
Figure 14 shows the flow chart of carrier synchronization method according to an aspect of the present invention；
Figure 15 shows the flow chart of carrier synchronization method according to an aspect of the present invention；
Figure 16 shows the arrangement schematic diagram of multipath channel；
Figure 17 shows training sequence according to an aspect of the present invention and the frequency range and power spectral density of data
Graph of a relation；And
Figure 18 shows two carrier signals according to an aspect of the present invention while frequency spectrum when sending data
Schematic diagram.
Embodiment
Below in conjunction with the drawings and specific embodiments, the present invention is described in detail.Note, below in conjunction with accompanying drawing and
The aspects of specific embodiment description is only exemplary, and is understood not to protection scope of the present invention
Carry out any limitation.
Except applying in OvTDM and OvFDM systems, all technologies described herein also can be extensive
Applied in actual GSM, such as TD-LTE, TD-SCDMA system also can extensive use
Communicated in satellite communication, microwave horizon communication, scatter communication, atmosphere optic communication, infrared communication with aquatic
Etc. in any wireless communication system.Term " network " and " system " are often used interchangeably.
Mobile communication continue to develop and new business emerge in an endless stream message transmission rate is proposed it is more next
Higher requirement, and the frequency resource of mobile communication is extremely limited, it is how real using limited frequency resource
The high-speed transfer of existing data turns into the major issue that current mobile communication technology faces
Above-mentioned OvTDM and OvFDM systems are exactly this can to greatly improve the solution party of the availability of frequency spectrum
Case.OvTDM systems are briefly described below sends and receives process.
OvTDM systems are using multiple symbols in time-domain transmitting data in parallel sequence.Form many in transmitting terminal
Individual symbol transmission signal overlapped in time-domain, in receiving terminal according to transmission data sequence and transmission number
According to the one-to-one relationship between sequence time waveform, docking is collected mail and presses data sequence in number progress time-domain
Detection.OvTDM systems actively using these it is overlapping be allowed to produce coding bound relation, so as to significantly carry
The high spectrum efficiency of system.
Fig. 1 shows the block diagram of the transmitting terminal modulation module of OvTDM systems.Transmitting terminal modulation module 100
It may include digital waveform generating unit 110, shifting deposit unit 120, multiplication unit 130 and adder unit
140。
First, first tune that generation sends signal is designed in a digital manner by digital waveform generating unit 110
The envelope waveform h (t) is carried out special time shifting by signal envelope waveform h (t) processed, shifting deposit unit 120
Position, forms the envelope waveform h (t-i × Δ T) of other each moment modulated signal, and multiplication unit 130 is by institute
The parallel symbol x to be sentiIt is multiplied with the envelope waveform h (t-i × Δ T) at corresponding moment, when obtaining each
Signal waveform x to be sent after quarter is modulatedih(t-i×ΔT).Adder unit 140 by formed each
Waveform to be sent is overlapped, and forms transmission signal waveform.
The receiving terminal of OvTDM systems is broadly divided into signal pre-processing module 200 and sequence detection module
300.Fig. 2 shows the block diagram of the signal pre-processing module 200 of the receiving terminal of OvTDM systems.Letter
Number pretreatment module, which is used to aiding in forming the synchronous of each frame in, receives digital signal sequences, as illustrated,
The signal pre-processing module may include synchronization unit 210, channel estimating unit 220 and digitized processing
Unit 230.
Synchronization unit 210 is used to dock the collection of letters number in time domain formation sign synchronization, to keep same with system
Step state, mainly includes Timing Synchronization and carrier synchronization.Rear channel estimating unit 220 is synchronously completed to dock
Channel estimation is done in the collection of letters number, for estimating the parameter of actual transmission channel.Digitized processing unit 230 is used
Processing is digitized in the reception signal to each frame in, so that forming suitable Sequence Detection part carries out sequence
Arrange the reception digital signal sequences of detection.
After pre-processing, the docking collection of letters number a Sequence Detection, docking can be carried out in sequence detection module 300
The waveform received is cut according to waveform transmission time interval and according to certain decoding algorithm to the ripple after cutting
Shape enters row decoding.Fig. 3 shows the block diagram of the receiving terminal sequence detection module of OvTDM systems.As schemed
Show, sequence detection module 300 may include analysis memory cell 310, comparing unit 320 and retain road
Footpath memory cell and Euclidean distance memory cell 330.In detection process, analysis memory cell is made
The complex convolution encoding model and trellis structure of OvTDM systems, and list whole states of OvTDM systems,
And store.Trellis structure of the comparing unit in analysis memory cell, is searched out with receiving data signal minimum
The path of Euclidean distance, and surviving path memory cell and Euclidean distance memory cell are then respectively used to storage ratio
The surviving path and Euclidean distance or weighted euclidean distance exported compared with unit.Surviving path memory cell and Euclidean
Need respectively to prepare one for each stable state apart from memory cell.Surviving path memory cell length can be with
Preferably 4K~5K.Euclidean distance memory cell is preferably only to store relative distance.
Fig. 4 shows the modulation module block diagram of the transmitting terminal of OvFDM systems.The OvFDM of transmitting terminal is adjusted
Molding block may include modulation carrier spectrum generation unit 410, carrier spectrum shift unit 420, multiplication unit
430th, adder unit 440 and Fourier inverse transformation unit 450.
First, the envelope frequency spectrum signal of one subcarrier of generation is designed by modulation carrier spectrum generation unit 410
H (f), carrier spectrum shift unit 420 by the envelope frequency spectrum signal H (f) successively frequency displacement specific carriers frequency
Interval delta B is composed, the envelope frequency spectrum signal of next subcarrier is drawn, and by the bag of next subcarrier
Network spectrum signal frequency displacement Δ B, goes down to obtain successively the spectrum waveform for all subcarriers that spectrum intervals is Δ B
H(f-i×ΔB)。
Multiplication unit 430 is by the symbol X for the multidiameter delay to be sentiIt is corresponding with generation each respectively
Individual subcarrier spectrum waveform H (f-i × Δ B) is multiplied, and obtains modulation of the multichannel Jing Guo corresponding subcarrier-modulated
Signal spectrum XiH(f-i×ΔB)。
The multiplexing signal spectrum formed is overlapped by adder unit 440, forms complex modulated signal
Frequency spectrumFinally, by Fourier inverse transformation unit 450 by the polyphony of generation
The frequency spectrum of signal processed carries out discrete Fu Shi inverse transformations, ultimately forms the complex modulated signal of time domain
Signal(t)TX=ifft (S (f)).
The receiving terminal of OvFDM systems is broadly divided into signal pre-processing module 500 and signal detection module
600.Fig. 5 shows the block diagram of the signal pre-processing module of the receiving terminal of OvFDM systems.As schemed
Show, pretreatment module may include synchronization unit 510, channel estimating unit 520 and digitized processing list
Member 530.
Synchronization unit 510 is used to dock the collection of letters number in time domain formation sign synchronization, to keep same with system
Step state, mainly includes Timing Synchronization and carrier synchronization.Rear channel estimating unit 520 is synchronously completed to dock
Channel estimation is done in the collection of letters number, for estimating the parameter of actual transmission channel.Digitized processing unit 530 is used
In the interval reception signal of each symbol time is sampled and quantified, it is allowed to be changed into digital signal sequences.
After pre-processing, the collection of letters number can be docked in signal detection module 600 to be detected.Fig. 6 is shown
The block diagram of the signal detection module 600 of the receiving terminal of OvFDM systems.As illustrated, signal detection
Module 600 may include Fourier transformation unit 610, frequency segmentation unit 620, convolutional encoding unit 630,
And data detecting unit 640.Fourier transformation unit 610 is used to turn the time-domain signal by pretreatment
Change frequency domain signal into, i.e., Fourier transform is carried out to the interval reception digital signal sequences of each time symbol
To form the actual receipt signal frequency spectrum that each time symbol is interval.Frequency segmentation unit 620 is used for each
The interval actual receipt signal frequency spectrum of time symbol is segmented in frequency domain with spectrum intervals Δ B, forms actual receive
Signal subsection frequency spectrum.Convolutional encoding unit 630 is used for the data symbol sequence for forming receipt signal frequency spectrum with sending
One-to-one relationship between row.Data detecting unit 640 is used for according to the formation of convolutional encoding unit one by one
Corresponding relation, detects data symbol sequence.
It is described above the processing procedure for sending and receiving end of OvTDM systems and OvFDM systems.To the greatest extent
Manage above-mentioned OvTDM systems and OvFDM systems have it is corresponding receive demodulation scheme exclude signal when
Domain or overlapping the brought interference of frequency domain, but the reception greatly improved still to signal of the availability of frequency spectrum
Propose requirements at the higher level.
Project training sequence is required in general communication system, its act on mainly after signal is received by
Processing, Timing Synchronization, carrier synchronization and channel estimation can be realized simultaneously.Timing Synchronization, carrier synchronization and letter
Road estimation is three most important links that receiving terminal is properly received.Therefore, the design of training symbol is most important,
Communication system especially for this superelevation spectrum efficiency of OvTDM and OvFDM systems is especially true.
If either step error is larger in these three steps, the influence to whole system will be very big, and follow-up translates
Code process is also just nonsensical.
Current communication system is training sequence frequently with M sequence, because M sequence auto-correlation and cross-correlation are special
Property is poor, causes system synchronization procedure success rate low, network insertion is slow.Fig. 7 shows oneself of M sequence
Correlation properties, as we can see from the figure its autocorrelation performance separated in time pulse can all occur, it is from phase
It is not fine to close characteristic.Therefore it is poor to the synchronization accuracy of time and frequency in signal processing, drop
The success rate and access speed of low user access network, make Consumer's Experience be deteriorated.
According to an aspect of the present invention, set in OvTDM systems and OvFDM systems using LAS codes
Count training sequence.It has been investigated that, there is LAS codes auto-correlation function to be preferable impulse function in origin,
It is zero everywhere beyond origin, and cross-correlation function is zero characteristic everywhere.This be for training sequence and
Its favourable attribute.
LAS (Large Area Synchronized, large area synchronous) code be by a series of pulses and
0 long value pulse spacing composition, can be expressed as (N, K, L), wherein N represents pulse number, K tables
Show the most short gap length between pulse, L represents code length.Pulse is generated by complete complementary orthogonal, and it is special
Point is preferable impulse function in origin for auto-correlation function, is zero everywhere beyond origin, and cross-correlation function
It is zero everywhere.It is applied to using this feature of LAS codes in OvTDM systems and OvFDM systems, it is right
There is preferable performance improvement in the synchronous success rate and access speed of whole system.
The generation method of LAS codes is introduced briefly below.
Complete complementary orthogonal has a duality relation, generation method be according to most short basic mutual-complementing code solve with
Complete orthogonal complement the most short basic mutual-complementing code of another pair.In present case with basic short code +++-generated
Standby complementary orthogonal, generating process is as follows：
C0=[1 1], are corresponded to ++, S0=[1-1], correspond to+-, according to C0And S0It is mutual that its is obtained respectively
Complement code C1And S1。C1For to S0Negate and obtain, S1For to C0Negating and asking to arrive, code in matlab
It is expressed as：
C1=fliplr (S0), S1=-1*conj (fliplr (C0)).Wherein fliplr for pair
Matrix carries out the function overturn along vertical axis or so, and conj is to seek complex conjugate function.
C is tried to achieve accordingly1=[- 1 1], S1=[- 1-1], by C0C1The new mutual-complementing code of combination producing is C0'=[1 1
- 1 1], S0'=[1-1-1-1], now the length of each mutual-complementing code extends to 4 by 2.
Here the length L of mutual-complementing code can be designedN(LNPower side for 2), i.e. CnAnd SnLength point
Wei not LN/2.Using the above method, the LAS codes of generation are iterated, its length is extended for LN,
Iterations is log2LN- 2, the mutual-complementing code ultimately generated is Cn、Sn。
By this to mutual-complementing code and null sequence combination producing LAS codes, representation is：Las=[Cn L0 Sn],
Wherein L0The number of expression 0, i.e. CnAnd SnBetween most short gap length, the LAS code lengths ultimately generated
Degree is expressed as L=LN+L0。
Fig. 8 shows the autocorrelation performance of LAS codes.
According to an aspect of the present invention, LAS codes are employed and carry out project training sequence.
For the purposes of Timing Synchronization, training sequence includes at least one LAS code.Because LAS short codes exist
Still there is preferable synchronous effect in the case that frequency deviation is larger, therefore, more preferably, training sequence includes at least one
Individual LAS short codes, with [Xlas]SNRepresent, the length of the wherein LAS short codes is designated as SN, its complementary code length
L is expressed as with null sequence lengthShort-N、LShort -0, SN=LShort-N+LShort -0。
In order to further optimize the autocorrelation performance of LAS codes, it may also include before the LAS short codes with being somebody's turn to do
One null sequence of LAS short code equal lengths, with [0]SNRepresent.
In specific embodiment, training sequence may include two identical LAS short codes, so wherein one
In the case that individual LAS short codes can be used for Timing Synchronization, LAS can also be constituted with another LAS short codes
Short code pair, for carrier synchronization.
For the purposes of carrier synchronization, training sequence may include at least one pair of identical LAS codes.Due to
LAS short codes still have preferable synchronous effect in the case where frequency deviation is larger, therefore, more preferably, training sequence
Including at least one pair of identical LAS short codes.
More preferably, carrier synchronization can be divided into the thick synchronous and carrier wave of two stages, i.e. carrier wave carefully synchronously.Therefore,
Training sequence may include at least two pairs LAS codes.More preferably, a pair of LAS codes can be identical LAS short codes
Slightly synchronous for carrier wave, another pair LAS codes can be identical LAS long codes, carefully same for carrier wave
Step.LAS long codes can use [Xlas]LNRepresent, the length of the wherein LAS long codes is designated as LN, its mutual-complementing code
Long and null sequence length is expressed as LLong-N、LLong -0, LN=LLong-N+LLong -0。
In order to further optimize the cross correlation of LAS codes, may also include before each LAS short codes with
One null sequence of LAS short code equal lengths, with [0]SNRepresent.
For the purposes of channel estimation, training sequence may include at least one LAS code, such as one
LAS long codes, or, two LAS long codes are may also comprise, are done twice for the two long LAS codes
Channel estimation, so as to improve the success rate of channel estimation.
As particular example, L can be designedLong-N=256, LLong -0=16；LShort-N=16, LShort -0=8.Certainly,
Here LAS long codes and the length of LAS short codes is only shown as example, may be designed as other length
Degree.
It is a kind of while meeting Timing Synchronization, carrier synchronization and channel estimation as preferably embodiment
LAS code training sequences may be designed as：[0]SN,[Xlas]SN,[0]SN,[Xlas]SN,[Xlas]LN,[Xlas]LN.It is real herein
Apply in example, first LAS code is short code, and Timing Synchronization can be achieved, and LAS short codes are larger still in frequency deviation
The synchronous effect having had.First and second LAS short code can be used for carrier wave slightly synchronous, short code it is good
Place is can to handle larger frequency deviation.Most latter two LAS code is long code, available for thin correcting frequency deviation and
Channel estimation.
Timing synchronization procedure
Receiver receives signal, it is necessary to first keep synchronous with communication system, including Timing Synchronization and carrier synchronization.
The principle of Timing Synchronization is, by matched filtering method, will directly to receive signal and asked with local LAS codes from phase
Computing is closed, autocorrelation peak is obtained.The position of training symbol is found according to certain method from correlation peak.
The position for finding training symbol has also determined that the original position of present frame, that is, completes reception signal and system
Time synchronized, timing synchronization procedure terminates.
As previously described, because the auto-correlation and cross correlation of LAS codes are all relatively good, LAS codes are used for
Project training symbol.Thus, when calculating the related operation for receiving signal and LAS codes, peak value size point
Cloth differs greatly, by reasonably setting threshold value, can accurately find very much the original position of LAS codes,
Timing accuracy is higher.
Specifically when finding the correlation peak of LAS codes, according to training symbol structure, suitable signal is taken
Length is received, using sliding window method auto-correlation computation mode, signal will be received to local LAS codes and seek related fortune
Calculate and find autocorrelation peak to determine the position of LAS codes.It can ensure for example, signal here receives length
At least covering has LAS codes, to guarantee to detect peak value.
So-called sliding window method auto-correlation computation, is that the docking collection of letters number is made by length of window of the length of LAS codes
Take window to handle, this segment signal in current window and local LAS codes are made into related operation, so as to obtain
One autocorrelation result.Then, window is slided backward, then docks a collection of letters number progress and take window, by current window
This intraoral segment signal remakes related operation with local LAS codes, so as to obtain a correlated results again.
In this way, continuous sliding window, until all having carried out related operation to the signal received.From calculating
The whole autocorrelation results drawn, by setting threshold value, i.e., more than threshold value autocorrelation result as peak value,
Find the position of LAS codes.
In one example, LAS code is only included in training sequence, such as one LAS short code, because
Short code still has preferable synchronous effect in the case where frequency deviation is larger.In this case, it is possible to by the LAS
The length of short code is collected mail as length of window docking number takes window to handle, by this segment signal in current window and
Local LAS short codes make related operation, so as to obtain an autocorrelation result.Then, by window backward
Slide, then dock the collection of letters number progresss and take window, by this segment signal in current window and local LAS codes again
Make related operation, so as to obtain a correlated results again.In this way, continuous sliding window, until docking
The signal received has all carried out related operation.From the whole autocorrelation results calculated, by setting threshold
Value, i.e., more than threshold value autocorrelation result as peak value, find the position of LAS codes.
In the case of multipath channel, it is possible to which the amplitude for several footpaths below occur exceeds the width in first footpath
Value, it should which choosing exceedes first peak point of threshold value, and is not necessarily global maximum.Fig. 9 shows fixed
When synchronous autocorrelation result distribution map.Assuming that threshold value is 100, as shown in figure 9, more than threshold value 100
Autocorrelation result have two, but be chosen at the autocorrelation results of 25 positions as the peak value of this computing,
So as to regard this as the position of the LAS codes found in 25 position.
In previous preferably training symbol format [0]SN,[Xlas]SN,[0]SN,[Xlas]SN,[Xlas]LN,[Xlas]LN's
In the case of, there are two LAS short codes in training sequence.Now, above-mentioned sliding window autocorrelation calculation is passed through
Method can find out two peak values for exceeding threshold value.Fig. 9 shows the autocorrelation result in the presence of two peak values
Distribution map.At this time, it may be necessary to judge which is the peak value in preceding short code, which is in rear short code
Peak value.
Figure 10 shows the schematic diagram for detecting the training sequence under two peak value situations.In Fig. 10
Show two training sequences that repetitive cycling is sent.Receive two training sequences of length spans of signal
Row, therefore, two peak values finding out may one of them be due to first of next training sequence
Caused by LAS short codes.So needing to judge which LAS short code corresponding to each peak value be.
Specifically, if two peak intervals length are 2*SN, then choose first and exceed threshold value
Peak value is the original position of first short LAS codes, if both gap lengths are more than 2*SN, second
The individual peak value more than threshold value is the original position of first short LAS code.
If there is multipath channel, then two part integrated distribution relevant peaks occur after sliding window, to every portion
The relevant peaks divided are compared with threshold value respectively, choose first peak point of threshold value, two parts are completeer
Two points for exceeding threshold value will be obtained afterwards, and the position of correspondence LAS codes is determined further according to method as above.
Then it is relatively light one by one after matched filtering in addition, if transmission signal have passed through other band limiting filters
Sliding peak, rather than independent point, so needing to choose peak point according to actual band limiting filter.
Figure 11 shows the block diagram of the time synchronization unit of receiving terminal according to an aspect of the present invention.This is determined
When synchronization unit can be a part above in association with Fig. 2 and Fig. 5 synchronization unit discussed.
As shown in figure 11, time synchronization unit 1100 may include autocorrelation calculation unit 1110 to hold
Row autocorrelation calculation.The autocorrelation calculation unit 1110 can carry out taking window to the signal received, to use
Local LAS codes make autocorrelation calculation to the signal in window, and slide the window to carry out next time certainly
Correlation computations, until reaching that signal receives length.Time synchronization unit 1100 may also include peak value and judge single
Member 1120, judges the position of peak value, to find LAS codes for the correlated results set according to acquisition
Original position.Peak value judging unit 1120 can choose suitable threshold value, by more than the auto-correlation knot of threshold value
Fruit is used as peak value.
Figure 12 shows the flow chart of time synchronization method according to an aspect of the present invention.As illustrated,
This method may include：
Step 1201：The signal received is carried out taking window, to use local LAS codes in window
Signal makees autocorrelation calculation, and slides the window to carry out autocorrelation calculation next time, until reaching that signal connects
Receive length；And
Step 1202：The position of peak value is judged according to the correlated results set of acquisition, to find LAS codes
Original position.
As described above, in the case where there are two LAS short codes, if two peak intervals length are
2*SN, then choose the original position that first peak value for exceeding threshold value is first short LAS codes, if
Both gap lengths are that then second exceedes the peak value of threshold value rising for first short LAS codes more than 2*SN
Beginning position.
Carrier synchronization process
Receive after signal, it is necessary to first keep synchronous with communication system, including Timing Synchronization and carrier synchronization,
The synchronization on signal and system first retention time is received, the original position of LAS codes is obtained by Timing Synchronization,
Enter the synchronization of line frequency again.
For carrier synchronization, receiving the training sequence message part of signal includes at least one pair of identical LAS
Code.Computing cross-correlation is carried out to the LAS codes repeated, frequency deviation f is obtained.
Assuming that the carrier deviation between receiver and emitter be Δ f, the AD sampling interval be T, then receiving terminal
When ignoring noise signal influence, the signal received is expressed as：
yn=xnej2πΔfnT
The coefficient correlation of former and later two LAS codes is：
Wherein L represents the interval between LAS codes.
From above formula, carrier wave frequency deviation is：
More preferably, training sequence message part may include two pairs of LAS codes, wherein, a pair of identical LAS
Code is LAS short codes, it is possible thereby to which it is slightly synchronous first to carry out carrier wave；Include a pair of identical LAS length again in addition
Code, it is possible thereby to which it is carefully synchronous to carry out carrier wave.
Due to having been completed Timing Synchronization, the training symbol that can be returned according to Timing Synchronization index is extracted pair
The short LAS codes of two parts answered, carrier wave are carried out to short LAS codes slightly synchronously, short code can handle larger frequency
Partially, it is Δ f that the frequency deviation value estimated is calculated according to above-mentioned formula1.Then the long LAS of two parts is extracted again
Code, the thin correcting frequency deviation of carrier wave is carried out to long LAS codes, and the frequency deviation value estimated is Δ f2, with reference to thick synchronization
Frequency deviation, then the frequency deviation of final output be Δ f=Δs f1+Δf2。
With previous preferably training symbol format [0]SN,[Xlas]SN,[0]SN,[Xlas]SN,[Xlas]LN,[Xlas]LNFor
Example.LN=272, SN=24 are made, training symbol total length is 640.Two short LAS exist respectively
(25:48) with (73:96) two positions, long LAS code divisions are not (97:368) with (369：640)
Two positions.
Ideally, the original position that Timing Synchronization calculates obtained LAS codes is first short LAS codes
Original position, as 25.It is right from signal is received according to this index and the code length LN and SN of long short code
That answers extracts corresponding code.
Carrier wave is slightly synchronous
The short LAS codes of two parts are extracted from signal is received, according to formulaConjugation is sought it
It is multiplied, obtains coefficient R.Further according to formulaObtain corresponding thick frequency deviation Δ f1,
Wherein L represents the interval between two short LAS codes, the L=2*SN=it can be seen from training symbol structure
48。
Thick frequency deviation according to calculating passes through formulaThe docking collection of letters number carries out a frequency offset correction,
Obtain the signal after first time frequency offset correction.
The thin frequency offset correction of carrier wave
The docking collection of letters number has carried out thick frequency offset correction in the thick synchronization of carrier wave, obtains receiving signal yn'.Thin frequency deviation
Process is from yn' in extract the long LAS codes of two parts, according to formulaConjugation phase is sought it
Multiply, obtain coefficient R.Further according to formulaObtain corresponding thin frequency deviation Δ f2,
L represents the interval between two long LAS codes, the L=LN=272 it can be seen from training symbol structure.
With reference to thick synchronous frequency deviation, then the frequency deviation of final output is Δ f=Δs f1+Δf2.And according to formula
yn"=yn'ej2π(-Δf)nTObtain the signal after the thin correcting frequency deviation of the docking collection of letters number.
By the signal y after frequency offset correction twicen" as input signal to channel estimation process, carrier synchronization mistake
Journey terminates.
Figure 13 shows the block diagram of carrier synchronization unit 1300.On the carrier synchronization unit 1300 can be
A part of the text with reference to Fig. 2 and Fig. 5 synchronization units discussed.
As illustrated, carrier synchronization unit 1300 may include cross-correlation calculation unit 1310 and frequency correction list
Member 1320.Cross-correlation calculation unit 1310 can perform cross-correlation calculation to obtain receiving terminal to a pair of LAS codes
The frequency deviation of carrier wave between transmitting terminal.Frequency correction unit 1320 can be according to the frequency deviation of the carrier wave, docking
The collection of letters number performs a frequency offset correction.
In one embodiment, the cross-correlation of a pair of LAS short codes can be first carried out in cross-correlation calculation unit 1310
Calculate, to obtain the thick frequency deviation of carrier wave between receiving terminal and transmitting terminal.Frequency correction unit 1320 can first root
According to the thick frequency deviation, the docking collection of letters number performs a first frequency offset correction.Cross-correlation calculation unit 1310 is again to from warp
A pair of LAS long codes execution cross-correlation calculation that the reception signal of first frequency offset correction is extracted is crossed, to obtain
The thin frequency deviation of carrier wave between receiving terminal and transmitting terminal.Frequency correction unit 1320 can further according to the thin frequency deviation and
The thick frequency deviation, performs secondary frequency offset correction, to obtain final frequency deviation to the reception signal through first frequency offset correction
Signal after correction.
Figure 14 shows the flow chart of the carrier synchronization method according to an embodiment.As illustrated, carrier wave is same
One step process may include following steps：
Step 1401：To performing cross-correlation from two LAS codes for receiving signal extraction, to obtain receiving terminal
The frequency deviation of carrier wave between transmitting terminal；And
Step 1402：A frequency offset correction is performed based on the frequency deviation docking collection of letters number.
Figure 15 shows the flow chart of the carrier synchronization method according to another embodiment.As illustrated, carrier wave
Synchronous method may include following steps：
Step 1501：To performing cross-correlation from two LAS short codes for receiving signal extraction, to be received
The thick frequency deviation of carrier wave between end and transmitting terminal；
Step 1502：According to the thick frequency deviation, the docking collection of letters number performs a first frequency offset correction；
Step 1503：A pair of the LAS long codes extracted from the reception signal through first frequency offset correction are performed
Cross-correlation calculation, to obtain the thin frequency deviation of carrier wave between receiving terminal and transmitting terminal；And
Step 1504：According to the thin frequency deviation and the thick frequency deviation, the reception signal through first frequency offset correction is held
The secondary frequency offset correction of row.
Although the above method is illustrated and is described as a series of actions to simplify explanation, it should be understood that simultaneously
Understand, the order that these methods are not acted is limited, because according to one or more embodiments, some actions
Can occur in different order and/or with from it is depicted and described herein or herein it is not shown and description but
Art personnel, which may be appreciated other actions, concomitantly to be occurred.
Channel estimation process
Channel estimation is used for the transmission characteristic for estimating channel, i.e., channel is to the influence of the signal transmitted.Pass through
Using training symbol known to transmitting terminal and receiving terminal both sides, receiving terminal can be according to the known training symbol
And the training symbol that receives performs channel estimation.For example, receiving terminal can be to known training
Symbol and the training symbol received perform correlation, so that it is determined that the transmission characteristic of channel.Carrying out channel
After estimation, receiving terminal can demodulate the unknown data signal received using identified channel estimation,
To determine the actual data signal of transmitting terminal transmission.
Receive signal and pass through Timing Synchronization, and system hold time synchronization.Then carrier wave is done with reception signal again
Synchronous, carrier synchronization includes thick synchronous and thin synchronous, passes through the synchronous carrier wave for obtaining receiver and transmitter
Frequency deviation Δ f, is corrected by carrier wave frequency deviation to the signal of reception, obtains revised reception signal yfix, to yfix
Do channel estimation.
The present invention is by the use of LAS codes as training sequence, such as the long LAS codes in training symbol format
L-LAS can be used for channel estimation.
Channel estimation is represented by：
Wherein ynRepresent to pass through the revised reception signal of carrier synchronization, i.e. yfix.N represents LAS code lengths.
xnRepresent local LAS codes, i.e. xnIt is expressed as most one of latter two long LAS code in training symbol.R0Table
Show the quadratic sum of LAS codes, P represents multipath channel number.
Reception signal y of the channel estimator from training symbolfixThe impulse response h (t) of middle estimation channel, then
One inverse channel system is constructed according to the h (t) estimated, the data-signal received passes through the inverse channel system
The estimation for the signal that channel is fed to transmitting terminal is reduced into afterwards.
It is general to receive signal ynIt can be expressed asenRepresent noise.Substituted into
Equation below is obtained after formula expansion：
The auto-correlation of training sequence is represented, is zero by rationally designing auto-correlation coefficient, estimation
Channel height is close to real channel, so as to drastically increase the precision of channel estimation.According to the present invention, by
The probability for occurring 0 in LAS codes auto-correlation is high, therefore substantially increases channel when carrying out channel estimation
The success rate of estimation.
This area typically carries out channel estimation using M sequence.The autocorrelation performance of the M sequence such as institute of accompanying drawing 7
Show, pulse can all occur in its autocorrelation performance separated in time as we can see from the figure, its autocorrelation performance
It is not fine, respective channels estimation formulas
InValue is not 0 probability
It is very big, therefore the channel model and ideal communication channel model bias that estimate are larger, are handled for follow-up decoding
Influence is very big, improves the bit error rate of system.
Contrast LAS code sequences, there is auto-correlation function to be preferable impulse function in origin for it, origin with
Outer is zero everywhere, and cross-correlation function is the characteristics of be zero everywhere, therefore when doing channel estimation, actual estimated
The channel model and ideal model deviation very little gone out, reduces the bit error rate of system, systematic function is obtained
Improve well.
According to the present invention, because long LAS codes have two in training symbol, therefore channel estimation process can
To be realized using the long LAS codes of any of which, or it can also be done twice for the two long LAS codes
Channel estimation, so as to improve the success rate of channel estimation.
A channel or multipath channel may be present in a communication environment, receiver can determine whether according to environment
There is multipath channel.In the case of no multipath channel, i.e. p=0 can be calculated directly according to above formula
Channel estimation h.And in the case where there is multipath channel, every multiple paths can be calculated respectively according to above formula
Channel estimation value hp, wherein for every multiple paths by local LAS codes xnEnter line displacement, each
The deviation in path can be 1.
For example, actual multipath channel can be such as 6.First by local LAS codes according to multipath
Number is arranged in 6 row, and the deviation in each row path is 1, and arrangement mode is as shown in Figure 16.
According to training symbol format [0]SN,[Xlas]SN,[0]SN,[Xlas]SN,[Xlas]LN,[Xlas]LN, from revise signal
yfixIn find corresponding LAS code positions, and extract as yfix-las, common two parts.
By the y extractedfix-lasRespectively with rearrange after 6 multipath channels local LAS codes pass through
Formula
After processing, the channel estimation value h of every multiple paths is obtainedp。
Because shared two parts LAS codes can carry out channel estimation, channel can be all obtained per part after treatment
Estimate hp, two parts are averaged, the channel estimation value h of every last multiple paths is can obtainp。
Then, can the channel estimation value h based on every multiple pathspTo demodulate the data-signal received, from
And the transmission end signal of every multiple paths must be recovered.
Project training sequence frequency range
Design symbols structure includes training sequence TSC (traning sequence code) and data in the system
(data).The design of training symbol is most important, and the timing, synchronization, channel that have impact on whole system are estimated
Three most important links are counted, if either step error is larger in these three steps, to the shadow of whole system
Sound will be very big, and follow-up decoding process is also just nonsensical.
The design process of training sequence frequency range is complex, when frequency range is shorter its corresponding power spectral density compared with
Greatly, the reception and transmission of data can be influenceed when there is multiple carrier waves in system, corresponding work(when frequency range is excessive
Rate spectrum density is too small, and the sensitivity requirement of transmitter and receiver to system is high.
It is general using training sequence and the frequency range identical method of data, its correspondence in existing communication system
Power spectral density it is identical, and due in General System frequency range it is all shorter, therefore corresponding to time domain send the time
Longer, influence signal is synchronous, channel estimation process time course, and the follow-up decoding process stand-by period is also elongated,
Reduce the transmission rate of system.Further, since the training sequence transmission time is longer, therefore enter to signal
During row sampling, its sample rate is relatively low, and temporal resolution is not fine enough, influences the deviation of channel estimation.
The invention enables training sequence frequency range much larger than data bandwidth (for example, 5 times, 10 times, 15 times or
More than), so that the power spectral density of training sequence is less than the power spectral density of data, its training sequence, number
According to frequency range and power spectral density graph of a relation as shown in Figure 17.Due to training sequence and the transmission work(of data
Rate need to be consistent, as can be seen from Figure, after the frequency range of training sequence broadens, its corresponding power spectrum
Density can consequently also be greatly lowered, and be very low for data power spectral density.
The system can use all available spreading codes, including m-sequence, Golomb codes, CAN (Cyclic
Algorithm New) and LAS codes etc..We are with complete complementary orthogonal property in the system
Exemplified by LAS codes, the processing procedure of Timing Synchronization, carrier synchronization and channel estimation is introduced.Therefore, institute above
That states is timed synchronization, carrier synchronization, all methods of channel estimation by the use of LAS codes as midamble code
And device is also applied for all suitable spreading codes and is timed synchronization, carrier wave and training as midamble code estimating
Meter.Therefore, above using LAS codes as the algorithm of the Timing Synchronization exemplified, carrier synchronization and channel estimation
It is merely possible to shown in example, the above of the invention is applied to all suitable midamble codes.
The characteristics of LAS codes is that auto-correlation function is to be everywhere beyond preferable impulse function, origin in origin
Zero, and cross-correlation function is zero everywhere, the autocorrelation performance of LAS codes is as shown in Figure 8.Therefore when training
Also will not mutually it be interfered during overlapping sequences.So design can improve the availability of frequency spectrum and the transmission of system
Speed.
By formulaUnderstand, when frequency domain frequency range is bigger, its correspondence is smaller in the time of time domain, that is, exists
Training sequence can be just completed in the shorter time sends and receives process.Process is received in signal, for
The data of same length, when 330 receiving between shorten, the sample rate of signal can be improved so that time resolution
Rate is finer.The accuracy of temporal resolution is improved in channel estimation process so that channel estimation results are more smart
Really.
On the one hand, because the power spectral density of training sequence is extremely low, shadow hardly is produced to data-signal
Ring, therefore training sequence and data can be superimposed in the same time and send.In other words, training sequence and data are
Send in frequency and/or at least partially overlappingly on time.When having two carrier signals while sending data
When, its structural map as shown in Figure 18, it can be seen that the real data that two carrier waves are carried
There is protection band centre, overlapping also will not will not mutually interfere；And the frequency range and real data of training sequence
Have overlapping, because training sequence power spectral density is very low, therefore real data will not be interfered；Again
Have, different training sequences can be distinguish between with different spreading codes, do not resulted in and obscured.Training sequence is not
Specific frequency and time resource are monopolized, the availability of frequency spectrum and transmission rate of system is improved.
In one embodiment, can be used in the system the LAS codes with complete complementary orthogonal property for
Training sequence, it is zero everywhere beyond preferable impulse function, origin that its feature is in origin for auto-correlation function,
And cross-correlation function is zero everywhere, the auto-correlation and cross correlation of LAS codes are as shown in Figure 5.Therefore work as
Also will not mutually it be interfered when training sequence is overlapping.So design can improve system the availability of frequency spectrum and
Transmission rate.
Our forms of project training sequence are in present case：
[0]SN,[Xlas]SN,[0]SN,[Xlas]SN,[Xlas]LN,[Xlas]LN。
It will be understood by those skilled in the art that various different technologies and skill can be used in information, signal and data
In any technology and skill represent.For example, above description quote from the whole text data, instruction, order,
Information, signal, position (bit), symbol and chip can be by voltage, electric current, electromagnetic wave, magnetic field or magnetic
Particle, light field or optical particle or its any combinations are represented.
Those skilled in the art will further appreciate that what is described with reference to the embodiments described herein is various
Illustrative logic plate, module, circuit and algorithm steps can realize for electronic hardware, computer software,
Or combination of the two.Clearly to explain this interchangeability of hardware and software, various illustrative components,
Frame, module, circuit and step are to make vague generalization description in its functional form above.Such work(
Energy property is implemented as hardware or software depends on concrete application and puts on the design constraint of total system.
Technical staff can realize described feature for every kind of application-specific with different modes, but such
Realize that decision-making should not be interpreted to cause departing from the scope of the present invention.
General place can be used with reference to the various illustrative logic modules and circuit that presently disclosed embodiment is described
Manage device, digital signal processor (DSP), application specific integrated circuit (ASIC), field programmable gate array
(FPGA) or other PLDs, discrete door or transistor logic, discrete nextport hardware component NextPort,
Or it is designed to carry out any combinations of function described herein to realize or perform.General processor can be
Microprocessor, but in alternative, the processor can be any conventional processor, controller, micro-
Controller or state machine.Processor is also implemented as the combination of computing device, such as DSP with it is micro-
The combination of processor, multi-microprocessor, the one or more microprocessors cooperated with DSP core or
Any other such configuration.
Can be embodied directly in hardware, in reference to the method that embodiment disclosed herein is described or the step of algorithm by
Embodied in the software module of computing device or in combination of the two.Software module can reside in RAM
Memory, flash memory, ROM memory, eprom memory, eeprom memory, register,
In hard disk, removable disk, the storage medium of CD-ROM or any other form known in the art.
Exemplary storage medium is coupled to processor to enable the processor to read and write from/to the storage medium
Information.In alternative, storage medium can be integrated into processor.Processor and storage medium can be stayed
Stay in ASIC.ASIC can reside in user terminal.In alternative, processor and storage are situated between
Matter can be resident in the user terminal as discrete assembly.
In one or more exemplary embodiments, described function can hardware, software, firmware or its
Realized in any combinations.If being embodied as computer program product in software, each function can be used as one
Bar or more bar is instructed or code storage is transmitted on a computer-readable medium or by it.It is computer-readable
Medium includes both computer-readable storage medium and communication media, and it includes facilitating computer program from a ground to another
Any medium of one ground transfer.Storage medium can be any usable medium that can be accessed by a computer.As
Example and it is non-limiting, such computer-readable medium may include RAM, ROM, EEPROM, CD-ROM
Other optical disc storages, disk storage or other magnetic storage apparatus or can be used to carry or store instruction or
The desirable program code of data structure form and any other medium that can be accessed by a computer.Any connection
It is properly termed a computer-readable medium.If for example, software be using coaxial cable, fiber optic cables,
The wireless skill of twisted-pair feeder, digital subscriber line (DSL) or such as infrared, radio and microwave etc
Art from web site, server or other remote sources transmit, then the coaxial cable, fiber optic cables,
The wireless technology of twisted-pair feeder, DSL or such as infrared, radio and microwave etc is just included in Jie
Among the definition of matter.As used herein disk (disk) and dish (disc) including compact disc (CD),
Laser disc, laser disc, digital versatile disc (DVD), floppy disk and blu-ray disc, which disk (disk) often with
The mode reproduce data of magnetic, and dish (disc) laser reproduce data optically.Combinations of the above
It should be included within the scope of computer readable media.
It is for so that any person skilled in the art all can make or make to provide of this disclosure be previously described
Use the disclosure.Various modifications of this disclosure all will be apparent for a person skilled in the art, and
The generic principles defined herein can be applied to spirit or model of other variants without departing from the disclosure
Enclose.Thus, the disclosure is not intended to be limited to example described herein and design, but should be awarded
Give the widest scope consistent with novel features with principle disclosed herein.
Claims (18)
1. a kind of signal processing method, including：
Pretreatment is performed to the reception signal from transmitting terminal, the signal that receives is believed by initial frequency domain data
Number time domain data signal generated after inverse fourier transform and the training sequence signal of time domain composition and described
The training sequence signal of time domain includes the training sequence based on LAS codes, and the execution pretreatment includes：
Pretreatment is performed to the reception signal using the training sequence based on LAS codes.
2. signal processing method as claimed in claim 1, it is characterised in that described to be based on described in
The training sequence of LAS codes performs pretreatment to the reception signal includes at least one of：
Timing Synchronization is performed to the reception signal using the training sequence based on LAS codes；
Carrier synchronization is performed to the reception signal using the training sequence based on LAS codes；Or
Channel estimation is performed to the reception signal using the training sequence based on LAS codes.
3. signal processing method as claimed in claim 2, it is characterised in that the training sequence includes
At least one LAS short code [Xlas]SN, SN is the length of the LAS short codes, described to be based on described in
The training sequence of LAS codes performs pretreatment to the reception signal to be included：
Timing Synchronization is performed to the reception signal using at least one described LAS short code.
4. signal processing method as claimed in claim 3, it is characterised in that the training sequence includes
Two LAS short codes, it is described that the reception signal is held using the training sequence based on LAS codes
Row pretreatment also includes：
Carrier synchronization is performed to the reception signal using described two LAS short codes.
5. signal processing method as claimed in claim 4, it is characterised in that the training sequence includes：
[0]SN,[Xlas]SN,[0]SN,[Xlas]SN, wherein [0]SNFor 0 sequence that length is SN.
6. signal processing method as claimed in claim 4, it is characterised in that the training sequence is also wrapped
Include two LAS long codes [Xlas]LN, LN is the length of the LAS long codes, described to be based on LAS using described
The training sequence of code performs pretreatment to the reception signal also to be included：
It is same using described two LAS long codes execution carrier wave secondary to the reception signal Jing Guo carrier synchronization
Step.
7. signal processing method as claimed in claim 6, it is characterised in that described to be based on described in
The training sequence of LAS codes performs pretreatment to the reception signal also to be included：
Channel is performed using any one of described two long LAS codes to the reception signal through carrier synchronization to estimate
Meter.
8. signal processing method as claimed in claim 6, it is characterised in that described to be based on described in
The training sequence of LAS codes performs pretreatment to the reception signal also to be included：
Channel estimation twice is performed to the reception signal through carrier synchronization using described two long LAS codes.
9. signal processing method as claimed in claim 6, it is characterised in that the training sequence includes：
[0]SN,[Xlas]SN,[0]SN,[Xlas]SN,[Xlas]LN,[Xlas]LN, wherein [0]SNFor 0 sequence that length is SN.
10. a kind of signal processing apparatus, including：
Pretreatment unit, for performing pretreatment to the reception signal from transmitting terminal, the reception signal by
Time domain data signal and the training sequence of time domain that initial frequency domain data signal is generated after inverse fourier transform
Column signal is constituted and the training sequence signal of the time domain includes the training sequence based on LAS codes, described pre-
Processing unit performs pretreatment using the training sequence based on LAS codes to the reception signal.
11. signal processing apparatus as claimed in claim 10, it is characterised in that pretreatment unit includes
At least one of：
Time synchronization unit, for being held using the training sequence based on LAS codes to the reception signal
Row Timing Synchronization；
Carrier synchronization unit, for being held using the training sequence based on LAS codes to the reception signal
Row carrier synchronization；Or
Channel estimating unit, for being held using the training sequence based on LAS codes to the reception signal
Row channel estimation.
12. signal processing apparatus as claimed in claim 11, it is characterised in that the training sequence bag
Include at least one LAS short code [Xlas]SN, SN is the length of the LAS short codes, the pretreatment unit
Including the time synchronization unit, the time synchronization unit is further used for using at least one described LAS
Short code performs Timing Synchronization to the reception signal.
13. signal processing apparatus as claimed in claim 12, it is characterised in that the training sequence bag
Two LAS short codes are included, the pretreatment unit also includes the carrier synchronization unit, the carrier wave
Synchronization unit is further used for performing carrier synchronization to the reception signal using described two LAS short codes.
14. signal processing apparatus as claimed in claim 13, it is characterised in that the training sequence bag
Include：[0]SN,[Xlas]SN,[0]SN,[Xlas]SN, wherein [0]SNFor 0 sequence that length is SN.
15. signal processing apparatus as claimed in claim 12, it is characterised in that the training sequence is also
Including two LAS long codes [Xlas]LN, LN is the length of the LAS long codes, the carrier synchronization unit
It is further used for performing using described two LAS long codes are secondary to the reception signal Jing Guo carrier synchronization
Carrier synchronization.
16. signal processing apparatus as claimed in claim 15, it is characterised in that the pretreatment unit
Also include the channel estimating unit, the channel estimating unit is further used for using described two long LAS
Any one of code performs channel estimation to the reception signal through carrier synchronization.
17. signal processing apparatus as claimed in claim 15, it is characterised in that the pretreatment unit
Also include the channel estimating unit, the channel estimating unit is further used for using described two long LAS
Code performs channel estimation twice to the reception signal through carrier synchronization.
18. signal processing apparatus as claimed in claim 15, it is characterised in that the training sequence bag
Include：[0]SN,[Xlas]SN,[0]SN,[Xlas]SN,[Xlas]LN,[Xlas]LN, wherein [0]SNFor 0 sequence that length is SN.
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